Awake craniotomy has become an increasingly frequent procedure. In this paper, the principles of its anaesthetic management are reviewed. The means allowing achievement of anaesthetic objectives are ... [more ▼]

Awake craniotomy has become an increasingly frequent procedure. In this paper, the principles of its anaesthetic management are reviewed. The means allowing achievement of anaesthetic objectives are described, with emphasis on points that determine success of the procedure. A careful and adequate selection and preparation of patients are mandatory, and the intervening team must be a skilled team. Choosing an awake technique or general anaesthesia depends on several factors, including the risk of obstructive apnoea, seizures, nausea and vomiting, patient's ability to cooperate, and localization of lesions. The main challenge of intraoperative anaesthetic management relies on the ability of rapidly adjusting the level of sedation and analgesia according to the sequence of surgical events, while ensuring haemodynamic stability, adequate ventilation, and minimal interference with eventual eletrophysiological recordings. Throughout the procedure, complications must be anticipated and managed according to predefined guidelines. More prospective randomized clinical trials are still needed to improve safety and efficacy of awake craniotomies, as well as to validate this technique in comparison with more conventional anaesthetic management. [less ▲]

In the last few years, transplantation was an area of intense research activity. However, there is a worldwide shortage of donor organs for clinical transplantations. Currently, interest in ... [more ▼]

In the last few years, transplantation was an area of intense research activity. However, there is a worldwide shortage of donor organs for clinical transplantations. Currently, interest in xenotransplantation research is growing not only because of the increased demand for organs but also because of advances in molecular biology techniques that make possible the genetic or immunological manipulations of the animal donor rather than the human recipient. The better definitions of the mechanisms responsible for xenograft rejection should facilitate appropriate therapeutic strategies for long xenograft survival. [less ▲]

Postischaemic reperfusion injury is often attributed to the generation of oxygenated free radicals which may subsequently promote lipid peroxidation in cell membranes. Electron paramagnetic resonance spectroscopy in association with the spin trap molecule alpha-phenyl-N-tert-butyl-nitrone allowed direct confirmation of lipid free radical production after renal ischaemia-reperfusion in an in vivo rabbit model. A 60-min period of ischaemia followed by reperfusion caused free radical production twofold greater than after 15 min of ischaemia. Glutathione and alpha-tocopherol have been measured in renal tissue, as indirect markers of lipid peroxidation. After 15 min of ischaemia followed by 10 min of reperfusion, the mean(s.e.m.) glutathione content of the ischaemic kidney was slightly but significantly reduced by 11.9(2.5)% (P < 0.003). The content of alpha-tocopherol was unchanged. However, 10 min of reperfusion following 60 min of ischaemia led to significant decrease in mean(s.e.m.) content of both glutathione (30.4(3.7)%) (2.23(0.2) versus 3.14(0.18) mumol/g wet tissue, P < 0.001) and alpha-tocopherol (46.1(7.8)%) (0.57(0.10) versus 1.09(0.14) micrograms/g wet tissue, P < 0.001) when compared to the control kidney. Under these experimental conditions, desferrioxamine (15 mg/kg administered intravenously before inducing ischaemia), a drug known to limit free radical production, significantly limited the decrease of alpha-tocopherol to 20.8(6.4)% (0.83(0.08) versus 1.05(0.04) micrograms/g wet tissue, P < 0.05), but did not prevent glutathione consumption in the reperfused kidney. [less ▲]

This preliminary study was designed to assess a possible role of neutrophil activation and to determine the prognostic value of plasma myeloperoxidase (MPO) and vitamin E (Vit. E) levels in severe head ... [more ▼]

This preliminary study was designed to assess a possible role of neutrophil activation and to determine the prognostic value of plasma myeloperoxidase (MPO) and vitamin E (Vit. E) levels in severe head injury. Plasma MPO and Vit. E levels were measured in nine severely head-injured patients (Glasgow Coma Score </=8) (ages 12-80 years) 6, 12. 18, 24, and 30 h after trauma. Patients were classified into two groups according to outcome after discharge from the ICU: group D (death; n = 5) and group S (survival; n = 4). Plasma MPO levels were increased immediately after trauma and then decreased. The MPO peak observed after 6 h was significantly higher (p < 0.05) in group D (mean +/- SEM: 1,237 +/- 122 ng/ml) than in group S (mean +/- SEM: 543 +/- 148 ng/ml). Plasma Vit. E levels were lower than normal values and decreased over time. They were always significantly lower (p < 0.05) in group D than in group S, except for the first sample. These differences cannot be explained entirely by total plasma lipid (TL) values since no statistical difference in TL concentrations was found between the two groups during the course of study. The ratio of Vit. E to TL. considered as the best index of Vit. E status, was lower in group D than in group S. and the difference reached statistical significance (p < 0.05) 12 h after trauma. In conclusion, in spite of the limited number of patients included in this study, it appears that severe head injury is associated with an increase in MPO and a decrease in Vit. E levels. These biochemical changes are of greater magnitude in group D than in group S; they suggest neutrophil activation and lipoperoxidation processes. Finally, plasma MPO and Vit. E seem to be new discriminant factors of outcome in head-injured patients. [less ▲]

Monitoring cerebral oxygen availability and utilization is of the utmost importance for patients with brain insults or potentially at risk of brain oxygen deprivation. The availability of the continuous ... [more ▼]

Monitoring cerebral oxygen availability and utilization is of the utmost importance for patients with brain insults or potentially at risk of brain oxygen deprivation. The availability of the continuous measurement of oxygen saturation in the jugular bulb questions the value of this parameter as an indicator of brain oxygenation. This article reviews the theoretical background and the practical aspects of this monitoring. It describes its possible applications to neurosurgical patients in the operating theater as well as in the intensive therapy unit. Finally, it comments on its main limitations which could impede an extensive utilization in clinical practice. [less ▲]

The present study of 43 patients with severe head injury shows that outcome prediction can be markedly improved by combining an appropriate marker of the degree of initial brain damage and other risk ... [more ▼]

The present study of 43 patients with severe head injury shows that outcome prediction can be markedly improved by combining an appropriate marker of the degree of initial brain damage and other risk factors. The patients were classified into three groups according to their actual outcome after 6 months: death (22 patients); persistent vegetative state or severe disability (eight patients); and moderate disability or good recovery (13 patients). By applying stepwise logistic discriminant analysis to the patients' data, five significant risk factors were selected: degree of neurological damage assessed by cerebrospinal fluid (CSF) extrapolated creatine kinase BB isoenzyme activity, Glasgow-Liege Coma Scale score, age, incidence of thoracic injury, and intracranial pressure (ICP). Extrapolated creatine kinase BB activity had the highest prognostic ability (67%). Uncontrollable elevated ICP proved to be systematically associated with death, whereas its absence was not necessarily indicative of a favorable outcome. The combination of the five variables yielded a total prognostic efficiency of 91%. The percentages of correctly predicted patients for the three outcome groups were, respectively, 100%, 50%, and 100%. Thus, half of the persistently vegetative and severely disabled patients were identified by the selected factors. [less ▲]